221512025 has 24 divisors (see below), whose sum is σ = 314860800. Its totient is φ = 151436160.

The previous prime is 221512021. The next prime is 221512033. The reversal of 221512025 is 520215122.

It is a happy number.

It is not a de Polignac number, because 221512025 - 2² = 221512021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221511988 and 221512006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221512021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 62501 + ... + 65949.

It is an arithmetic number, because the mean of its divisors is an integer number (13119200).

Almost surely, 2^221512025 is an apocalyptic number.

221512025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221512025 is a deficient number, since it is larger than the sum of its proper divisors (93348775).

221512025 is a wasteful number, since it uses less digits than its factorization.

221512025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3833 (or 3828 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 221512025 is about 14883.2800484302. The cubic root of 221512025 is about 605.0609186660.

Adding to 221512025 its reverse (520215122), we get a palindrome (741727147).

The spelling of 221512025 in words is "two hundred twenty-one million, five hundred twelve thousand, twenty-five".